Social media and the leadership debates – BBC News
"All of this activity on social networks, on blogs and on the mainstream media will be analysed by practitioners of a new discipline called sentiment analysis.
They believe that by feeding vast amounts of data into computers they can analyse the emotions of those people watching and commenting on an event, and say something useful about public opinion.
The technology is already employed to help financial traders make decisions about the impact of sentiment on the markets.
The three television debates will be a useful testing ground for the claims of this new science."
(Link has great overview of Twitter and Facebook activity during campaign.)